Re: [PATCH 1/2] s390x/pci: bypass vfio DMA counting when using cdev

[Philippe Mathieu-Daudé]

[Sent too fast by inadvertence...]

Hi Matthew,

On 10/11/23 06:21, Philippe Mathieu-Daudé wrote:
> On 9/11/23 23:53, Matthew Rosato wrote:
> > The current code assumes that there is always a vfio group, but
> > that's no longer guaranteed with the iommufd backend when using
> > cdev.  In this case, we don't need to track the vfio dma limit
> > anyway.
> >
> > Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
> > ---
> >   hw/s390x/s390-pci-vfio.c | 6 +++++-
> >   1 file changed, 5 insertions(+), 1 deletion(-)
> >
> > diff --git a/hw/s390x/s390-pci-vfio.c b/hw/s390x/s390-pci-vfio.c
> > index 59a2e03873..7218583883 100644
> > --- a/hw/s390x/s390-pci-vfio.c
> > +++ b/hw/s390x/s390-pci-vfio.c
> > @@ -66,7 +66,11 @@ S390PCIDMACount 
> > *s390_pci_start_dma_count(S390pciState *s,
> >       assert(vpdev);
>
> Matter of taste, simpler as:
>
>         if (!vpdev->vbasedev.group) {
>             return NULL;
>         }
>
> > -    id = vpdev->vbasedev.group->container->fd;
>
> and this line isn't changed.
>
> > +    if (vpdev->vbasedev.group) {
> > +        id = vpdev->vbasedev.group->container->fd;
> > +    } else {
> > +        return NULL;
> > +    }
> >       if (!s390_pci_update_dma_avail(id, &avail)) {
> >           return NULL;

Regards,

Phil :)